I'm thinking of selling my 760 windforce and save some more and get a 780 poseidon. Can I run the 780 poseidon with my EVGA 500W 80+ bronze psu? or do I really need the 600w one? How much can I get for my 760 windforce? thinking of selling near the summer It'll be around 4 months used then and I bought it for $300+ here in canada.